Data Sheet
FEATURES:
• Single 3.0-3.6V Read and Write Operations• Serial Interface Architecture
– SPI Compatible: Mode 0 and Mode 3• 33 MHz Max Clock Frequency• Superior Reliability
– Endurance: 100,000 Cycles (typical)– Greater than 100 years Data Retention
• Low Power Consumption:– Active Read Current: 7 mA (typical)– Standby Current: 8 µA (typical)
• Flexible Erase Capability– Uniform 4 KByte sectors– Uniform 32 KByte overlay blocks
• Fast Erase and Byte-Program:– Chip-Erase Time: 70 ms (typical)– Sector- or Block-Erase Time: 18 ms (typical)– Byte-Program Time: 14 µs (typical)
• Auto Address Increment (AAI) Programming– Decrease total chip programming time over
Byte-Program operations
• End-of-Write Detection– Software Status
• Hold Pin (HOLD#)– Suspends a serial sequence to the memory
without deselecting the device• Write Protection (WP#)
– Enables/Disables the Lock-Down function of the status register
• Software Write Protection– Write protection through Block-Protection bits in
status register• Temperature Range
– Commercial: 0°C to +70°C– Industrial: -40°C to +85°C– Extended: -20°C to +85°C
• Packages Available– 8-lead SOIC 150 mil body width
for SST25LF020A– 8-contact WSON (5mm x 6mm)
• All non-Pb (lead-free) devices are RoHS compliant
2 Mbit SPI Serial FlashSST25LF020A
SST25LF020A / 040A2Mb / 4Mb Serial Peripheral Interface (SPI) flash memory
PRODUCT DESCRIPTION
SST’s serial flash family features a four-wire, SPI-com-patible interface that allows for a low pin-count packageoccupying less board space and ultimately lowering totalsystem costs. SST25LF020A SPI serial flash memoriesare manufactured with SST’s proprietary, high perfor-mance CMOS SuperFlash technology. The split-gate celldesign and thick-oxide tunneling injector attain better reli-ability and manufacturability compared with alternateapproaches.
The SST25LF020A devices significantly improve perfor-mance, while lowering power consumption. The totalenergy consumed is a function of the applied voltage, cur-
rent, and time of application. Since for any given voltagerange, the SuperFlash technology uses less current toprogram and has a shorter erase time, the total energyconsumed during any Erase or Program operation is lessthan alternative flash memory technologies. TheSST25LF020A devices operate with a single 3.0-3.6Vpower supply.
The SST25LF020A devices are offered in an 8-lead SOIC150 mil body width (SA) package, and in an 8-contactWSON package. See Figure 2 for the pin assignments.
©2010 Silicon Storage Technology, Inc.S71242-07-000 01/101
The SST logo and SuperFlash are registered Trademarks of Silicon Storage Technology, Inc.These specifications are subject to change without notice.
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
FIGURE 1: Functional Block Diagram
1242 B1.0
I/O Buffersand
Data Latches
SuperFlashMemoryX - Decoder
Control Logic
AddressBuffers
andLatches
CE#
Y - Decoder
SCK SI SO WP# HOLD#
Serial Interface
2©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
PIN DESCRIPTION
FIGURE 2: Pin Assignments
TABLE 1: Pin Description
Symbol Pin Name Functions
SCK Serial Clock To provide the timing of the serial interface.Commands, addresses, or input data are latched on the rising edge of the clock input, while output data is shifted out on the falling edge of the clock input.
SI Serial DataInput
To transfer commands, addresses, or data serially into the device.Inputs are latched on the rising edge of the serial clock.
SO Serial DataOutput
To transfer data serially out of the device.Data is shifted out on the falling edge of the serial clock.
CE# Chip Enable The device is enabled by a high to low transition on CE#. CE# must remain low for the duration of any command sequence.
WP# Write Protect The Write Protect (WP#) pin is used to enable/disable BPL bit in the status register.
HOLD# Hold To temporarily stop serial communication with SPI flash memory without resetting the device.
VDD Power Supply To provide power supply (3.0-3.6V).
VSS GroundT1.0 1242
8-lead SOIC 8-contact WSON
1
2
3
4
8
7
6
5
CE#
SO
WP#
VSS
Top View
VDD
HOLD#
SCK
SI
1242 08-wson P2.0
1
2
3
4
8
7
6
5
CE#
SO
WP#
VSS
VDD
HOLD#
SCK
SI
Top View
1242 08-soic P1.0
3©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
PRODUCT IDENTIFICATION
MEMORY ORGANIZATION
The SST25LF020A SuperFlash memory array is orga-nized in 4 KByte sectors with 32 KByte overlay blocks.
DEVICE OPERATION
The SST25LF020A is accessed through the SPI (SerialPeripheral Interface) bus compatible protocol. The SPI busconsist of four control lines; Chip Enable (CE#) is used toselect the device, and data is accessed through the SerialData Input (SI), Serial Data Output (SO), and Serial Clock(SCK).
The SST25LF020A supports both Mode 0 (0,0) and Mode3 (1,1) of SPI bus operations. The difference between thetwo modes, as shown in Figure 3, is the state of the SCKsignal when the bus master is in Stand-by mode and nodata is being transferred. The SCK signal is low for Mode 0and SCK signal is high for Mode 3. For both modes, theSerial Data In (SI) is sampled at the rising edge of the SCKclock signal and the Serial Data Output (SO) is driven afterthe falling edge of the SCK clock signal.
FIGURE 3: SPI Protocol
TABLE 2: Product Identification
Address Data
Manufacturer’s ID 00000H BFH
Device ID
SST25LF020A 00001H 43HT2.0 1242
1242 F02.0
MODE 3
SCK
SI
SO
CE#
MODE 3
DON'T CARE
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1Bit 0
MODE 0MODE 0
HIGH IMPEDANCEMSB
MSB
4©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Hold OperationHOLD# pin is used to pause a serial sequence underwaywith the SPI flash memory without resetting the clockingsequence. To activate the HOLD# mode, CE# must be inactive low state. The HOLD# mode begins when the SCKactive low state coincides with the falling edge of theHOLD# signal. The HOLD mode ends when the HOLD#signal’s rising edge coincides with the SCK active low state.
If the falling edge of the HOLD# signal does not coincidewith the SCK active low state, then the device enters Holdmode when the SCK next reaches the active low state.Similarly, if the rising edge of the HOLD# signal does not
coincide with the SCK active low state, then the deviceexits in Hold mode when the SCK next reaches the activelow state. See Figure 4 for Hold Condition waveform.
Once the device enters Hold mode, SO will be in high-impedance state while SI and SCK can be VIL or VIH.
If CE# is driven active high during a Hold condition, it resetsthe internal logic of the device. As long as HOLD# signal islow, the memory remains in the Hold condition. To resumecommunication with the device, HOLD# must be drivenactive high, and CE# must be driven active low. See Figure19 for Hold timing.
FIGURE 4: Hold Condition Waveform
Write ProtectionSST25LF020A provides software Write protection. TheWrite Protect pin (WP#) enables or disables the lock-downfunction of the status register. The Block-Protection bits(BP1, BP0, and BPL) in the status register provide Writeprotection to the memory array and the status register. SeeTable 5 for Block-Protection description.
Write Protect Pin (WP#)
The Write Protect (WP#) pin enables the lock-down func-tion of the BPL bit (bit 7) in the status register. When WP#is driven low, the execution of the Write-Status-Register(WRSR) instruction is determined by the value of the BPLbit (see Table 3). When WP# is high, the lock-down func-tion of the BPL bit is disabled.
Active Hold Active Hold Active
1242 F03.0
SCK
HOLD#
TABLE 3: Conditions to execute Write-Status-Register (WRSR) Instruction
WP# BPL Execute WRSR Instruction
L 1 Not Allowed
L 0 Allowed
H X AllowedT3.0 1242
5©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Status RegisterThe software status register provides status on whether theflash memory array is available for any Read or Write oper-ation, whether the device is Write enabled, and the state ofthe memory Write protection. During an internal Erase or
Program operation, the status register may be read only todetermine the completion of an operation in progress.Table 4 describes the function of each bit in the softwarestatus register.
Busy
The Busy bit determines whether there is an internal Eraseor Program operation in progress. A “1” for the Busy bit indi-cates the device is busy with an operation in progress. A “0”indicates the device is ready for the next valid operation.
Write Enable Latch (WEL)
The Write-Enable-Latch bit indicates the status of the inter-nal memory Write Enable Latch. If the Write-Enable-Latchbit is set to “1”, it indicates the device is Write enabled. If thebit is set to “0” (reset), it indicates the device is not Writeenabled and does not accept any memory Write (Program/Erase) commands. The Write-Enable-Latch bit is automati-cally reset under the following conditions:
• Power-up• Write-Disable (WRDI) instruction completion• Byte-Program instruction completion• Auto Address Increment (AAI) programming
reached its highest memory address• Sector-Erase instruction completion• Block-Erase instruction completion• Chip-Erase instruction completion
TABLE 4: Software Status Register
Bit Name FunctionDefault atPower-up Read/Write
0 BUSY 1 = Internal Write operation is in progress0 = No internal Write operation is in progress
0 R
1 WEL 1 = Device is memory Write enabled0 = Device is not memory Write enabled
0 R
2 BP0 Indicate current level of block write protection (See Table 5) 1 R/W
3 BP1 Indicate current level of block write protection (See Table 5) 1 R/W
4:5 RES Reserved for future use 0 N/A
6 AAI Auto Address Increment Programming status1 = AAI programming mode0 = Byte-Program mode
0 R
7 BPL 1 = BP1, BP0 are read-only bits0 = BP1, BP0 are read/writable
0 R/W
T4.0 1242
6©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Block Protection (BP1, BP0)
The Block-Protection (BP1, BP0) bits define the size of thememory area, as defined in Table 5, to be software pro-tected against any memory Write (Program or Erase)operations. The Write-Status-Register (WRSR) instructionis used to program the BP1 and BP0 bits as long as WP#is high or the Block-Protect-Lock (BPL) bit is 0. Chip-Erasecan only be executed if Block-Protection bits are both 0.After power-up, BP1 and BP0 are set to 1.
Block Protection Lock-Down (BPL)
WP# pin driven low (VIL), enables the Block-Protection-Lock-Down (BPL) bit. When BPL is set to 1, it prevents anyfurther alteration of the BPL, BP1, and BP0 bits. When theWP# pin is driven high (VIH), the BPL bit has no effect andits value is “Don’t Care”. After power-up, the BPL bit isreset to 0.
Auto Address Increment (AAI)
The Auto Address Increment Programming-Status bit pro-vides status on whether the device is in AAI programmingmode or Byte-Program mode. The default at power up isByte-Program mode.
TABLE 5: Software Status Register Block Protection1
1. Default at power-up for BP1 and BP0 is ‘11’.
Protection Level
Status Register
BitProtected Memory Area
BP1 BP0 2 Mbit
0 0 0 None
1 (1/4 Memory Array) 0 1 030000H-03FFFFH
2 (1/2 Memory Array) 1 0 020000H-03FFFFH
3 (Full Memory Array) 1 1 000000H-03FFFFHT5.0 1242
7©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
InstructionsInstructions are used to Read, Write (Erase and Program),and configure the SST25LF020A. The instruction buscycles are 8 bits each for commands (Op Code), data, andaddresses. Prior to executing any Byte-Program, AutoAddress Increment (AAI) programming, Sector-Erase,Block-Erase, or Chip-Erase instructions, the Write-Enable(WREN) instruction must be executed first. The completelist of the instructions is provided in Table 6. All instructionsare synchronized off a high to low transition of CE#. Inputswill be accepted on the rising edge of SCK starting with the
most significant bit. CE# must be driven low before aninstruction is entered and must be driven high after the lastbit of the instruction has been shifted in (except for Read,Read-ID and Read-Status-Register instructions). Any lowto high transition on CE#, before receiving the last bit of aninstruction bus cycle, will terminate the instruction inprogress and return the device to the standby mode.Instruction commands (Op Code), addresses, and data areall input from the most significant bit (MSB) first.
TABLE 6: Device Operation Instructions1
1. AMS = Most Significant AddressAMS = A17 for SST25LF020A Address bits above the most significant bit of each density can be VIL or VIH
Cycle Type/Operation2,3
2. Operation: SIN = Serial In, SOUT = Serial Out3. X = Dummy Input Cycles (VIL or VIH); - = Non-Applicable Cycles (Cycles are not necessary)
MaxFreqMHz
Bus Cycle4
4. One bus cycle is eight clock periods.
1 2 3 4 5 6
SIN SOUT SIN SOUT SIN SOUT SIN SOUT SIN SOUT SIN SOUT
Read 20 03H Hi-Z A23-A16 Hi-Z A15-A8 Hi-Z A7-A0 Hi-Z X DOUT
High-Speed-Read
33
0BH Hi-Z A23-A16 Hi-Z A15-A8 Hi-Z A7-A0 Hi-Z X X X DOUT
Sector-Erase5,6
5. Sector addresses: use AMS-A12, remaining addresses can be VIL or VIH
6. Prior to any Byte-Program, AAI-Program, Sector-Erase, Block-Erase, or Chip-Erase operation, the Write-Enable (WREN) instruction must be executed.
20H Hi-Z A23-A16 Hi-Z A15-A8 Hi-Z A7-A0 Hi-Z - -
Block-Erase5,7
7. Block addresses for: use AMS-A15, remaining addresses can be VIL or VIH
52H Hi-Z A23-A16 Hi-Z A15-A8 Hi-Z A7-A0 Hi-Z - -
Chip-Erase6 60H Hi-Z - - - - - - - -
Byte-Program6 02H Hi-Z A23-A16 Hi-Z A15-A8 Hi-Z A7-A0 Hi-Z DIN Hi-Z
Auto Address Increment(AAI) Single-Byte Program6,8
8. To continue programming to the next sequential address location, enter the 8-bit command, AFH, followed by the data to be programmed.
AFH Hi-Z A23-A16 Hi-Z A15-A8 Hi-Z A7-A0 Hi-Z DIN Hi-Z
Read-Status-Register(RDSR)
05H Hi-Z X DOUT - Note9
9. The Read-Status-Register is continuous with ongoing clock cycles until terminated by a low to high transition on CE#.
- Note9 - Note9
Enable-Write-Status-Register(EWSR)10
10. The Enable-Write-Status-Register (EWSR) instruction and the Write-Status-Register (WRSR) instruction must work in conjunction of each other. The WRSR instruction must be executed immediately (very next bus cycle) after the EWSR instruction to make both instructions effective.
50H Hi-Z - - - - - - - -
Write-Status-Register(WRSR)10
01H Hi-Z Data Hi-Z - - -. - - -
Write-Enable (WREN) 06H Hi-Z - - - - - - - -
Write-Disable (WRDI) 04H Hi-Z - - - - - - - -
Read-ID 90H orABH
Hi-Z 00H Hi-Z 00H Hi-Z IDAddr11
11. Manufacturer’s ID is read with A0=0, and Device ID is read with A0=1. All other address bits are 00H. The Manufacturer and Device ID output stream is continuous until terminated by a low to high transition on CE#
Hi-Z X DOUT12
12. Device ID = 43H for SST25LF020A
T6.0 1242
8©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Read (20 MHz)
The Read instruction supports up to 20 MHz, it outputs thedata starting from the specified address location. The dataoutput stream is continuous through all addresses until ter-minated by a low to high transition on CE#. The internaladdress pointer will automatically increment until the high-est memory address is reached. Once the highest memoryaddress is reached, the address pointer will automaticallyincrement to the beginning (wrap-around) of the address
space, i.e. for 2 Mbit density, once the data from addresslocation 3FFFFH had been read, the next output will befrom address location 00000H.
The Read instruction is initiated by executing an 8-bit com-mand, 03H, followed by address bits [A23-A0]. CE# mustremain active low for the duration of the Read cycle. SeeFigure 5 for the Read sequence.
FIGURE 5: Read Sequence
1242 F04.0
CE#
SO
SI
SCK
ADD.
0 1 2 3 4 5 6 7 8
ADD. ADD.03
HIGH IMPEDANCE
15 16 23 24 31 32 39 40 7047 48 55 56 63 64
N+2 N+3 N+4N N+1DOUT
MSB MSB
MSB
MODE 0
MODE 3
DOUT DOUT DOUT DOUT
9©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
High-Speed-Read (33 MHz)
The High-Speed-Read instruction supporting up to 33 MHzis initiated by executing an 8-bit command, 0BH, followedby address bits [A23-A0] and a dummy byte. CE# mustremain active low for the duration of the High-Speed-Readcycle. See Figure 6 for the High-Speed-Read sequence.
Following a dummy byte (8 clocks input dummy cycle), theHigh-Speed-Read instruction outputs the data starting fromthe specified address location. The data output stream iscontinuous through all addresses until terminated by a low
to high transition on CE#. The internal address pointer willautomatically increment until the highest memory addressis reached. Once the highest memory address is reached,the address pointer will automatically increment to thebeginning (wrap-around) of the address space, i.e. for2 Mbit density, once the data from address location03FFFFH has been read, the next output will be fromaddress location 000000H.
FIGURE 6: High-Speed-Read Sequence
1242 F05.0
CE#
SO
SI
SCK
ADD.
0 1 2 3 4 5 6 7 8
ADD. ADD.0B
HIGH IMPEDANCE
15 16 23 24 31 32 39 40 47 48 55 56 63 64
N+2 N+3 N+4N N+1
X
MSB
MSBMSB
MODE 0
MODE 3
DOUT DOUT DOUT DOUT
8071 72
DOUT
Note: X = Dummy Byte: 8 Clocks Input Dummy Cycle (VIL or VIH)
10©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Byte-Program
The Byte-Program instruction programs the bits in theselected byte to the desired data. The selected byte mustbe in the erased state (FFH) when initiating a Programoperation. A Byte-Program instruction applied to a pro-tected memory area will be ignored.
Prior to any Write operation, the Write-Enable (WREN)instruction must be executed. CE# must remain active lowfor the duration of the Byte-Program instruction. The Byte-
Program instruction is initiated by executing an 8-bit com-mand, 02H, followed by address bits [A23-A0]. Following theaddress, the data is input in order from MSB (bit 7) to LSB(bit 0). CE# must be driven high before the instruction isexecuted. The user may poll the Busy bit in the softwarestatus register or wait TBP for the completion of the internalself-timed Byte-Program operation. See Figure 7 for theByte-Program sequence.
FIGURE 7: Byte-Program Sequence
1242 F06.0
CE#
SO
SI
SCK
ADD.
0 1 2 3 4 5 6 7 8
ADD. ADD. DIN02
HIGH IMPEDANCE
15 16 23 24 31 32 39
MODE 0
MODE 3
MSBMSBMSB LSB
11©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Auto Address Increment (AAI) Program
The AAI program instruction allows multiple bytes of data tobe programmed without re-issuing the next sequentialaddress location. This feature decreases total program-ming time when the entire memory array is to be pro-grammed. An AAI program instruction pointing to aprotected memory area will be ignored. The selectedaddress range must be in the erased state (FFH) when ini-tiating an AAI program instruction.
Prior to any write operation, the Write-Enable (WREN)instruction must be executed. The AAI program instructionis initiated by executing an 8-bit command, AFH, followedby address bits [A23-A0]. Following the addresses, the datais input sequentially from MSB (bit 7) to LSB (bit 0). CE#must be driven high before the AAI program instruction isexecuted. The user must poll the BUSY bit in the software
status register or wait TBP for the completion of each inter-nal self-timed Byte-Program cycle. Once the device com-pletes programming byte, the next sequential address maybe program, enter the 8-bit command, AFH, followed by thedata to be programmed. When the last desired byte hadbeen programmed, execute the Write-Disable (WRDI)instruction, 04H, to terminate AAI. After execution of theWRDI command, the user must poll the Status register toensure the device completes programming. See Figure 8for AAI programming sequence.
There is no wrap mode during AAI programming; once thehighest unprotected memory address is reached, thedevice will exit AAI operation and reset the Write-Enable-Latch bit (WEL = 0).
FIGURE 8: Auto Address Increment (AAI) Program Sequence
CE#
SI
SCK
A[23:16] A[15:8] A[7:0]AF Data Byte 1 AF Data Byte 2
CE#
SI
SO
SCK
Write Disable (WRDI)Instruction to terminateAAI Operation
Read Status Register (RDSR)Instruction to verify end ofAAI Operation
04Last Data ByteAF 05
DOUT
MODE 3
MODE 0
TBP TBP
TBP
1242 F07.0
0 1 2 3 4 5 6 7 8 32 33 34 35 36 37 38 3915 16 23 24 31 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 1
0 1 2 3 4 5 6 70 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
12©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Sector-Erase
The Sector-Erase instruction clears all bits in the selected 4KByte sector to FFH. A Sector-Erase instruction applied toa protected memory area will be ignored. Prior to any Writeoperation, the Write-Enable (WREN) instruction must beexecuted. CE# must remain active low for the duration ofthe any command sequence. The Sector-Erase instructionis initiated by executing an 8-bit command, 20H, followedby address bits [A23-A0]. Address bits [AMS-A12]
(AMS = Most Significant address) are used to determine thesector address (SAX), remaining address bits can be VIL orVIH. CE# must be driven high before the instruction is exe-cuted. The user may poll the Busy bit in the software statusregister or wait TSE for the completion of the internal self-timed Sector-Erase cycle. See Figure 9 for the Sector-Erase sequence.
FIGURE 9: Sector-Erase Sequence
Block-Erase
The Block-Erase instruction clears all bits in the selected 32KByte block to FFH. A Block-Erase instruction applied to aprotected memory area will be ignored. Prior to any Writeoperation, the Write-Enable (WREN) instruction must beexecuted. CE# must remain active low for the duration ofany command sequence. The Block-Erase instruction isinitiated by executing an 8-bit command, 52H, followed by
address bits [A23-A0]. Address bits [AMS-A15] (AMS = Mostsignificant address) are used to determine block address(BAX), remaining address bits can be VIL or VIH. CE# mustbe driven high before the instruction is executed. The usermay poll the Busy bit in the software status register or waitTBE for the completion of the internal self-timed Block-Erase cycle. See Figure 10 for the Block-Erase sequence.
FIGURE 10: Block-Erase Sequence
CE#
SO
SI
SCK
ADD.
0 1 2 3 4 5 6 7 8
ADD. ADD.20
HIGH IMPEDANCE
15 16 23 24 31
MODE 0
MODE 3
1242 F08.0
MSBMSB
CE#
SO
SI
SCK
ADD.
0 1 2 3 4 5 6 7 8
ADD. ADD.52
HIGH IMPEDANCE
15 16 23 24 31
MODE 0
MODE 3
1242 F09.0
MSB MSB
13©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Chip-Erase
The Chip-Erase instruction clears all bits in the device toFFH. A Chip-Erase instruction will be ignored if any of thememory area is protected. Prior to any Write operation, theWrite-Enable (WREN) instruction must be executed. CE#must remain active low for the duration of the Chip-Eraseinstruction sequence. The Chip-Erase instruction is initiated
by executing an 8-bit command, 60H. CE# must be drivenhigh before the instruction is executed. The user may pollthe Busy bit in the software status register or wait TCE forthe completion of the internal self-timed Chip-Erase cycle.See Figure 11 for the Chip-Erase sequence.
FIGURE 11: Chip-Erase Sequence
Read-Status-Register (RDSR)
The Read-Status-Register (RDSR) instruction allows read-ing of the status register. The status register may be read atany time even during a Write (Program/Erase) operation.When a Write operation is in progress, the Busy bit may bechecked before sending any new commands to assure thatthe new commands are properly received by the device.
CE# must be driven low before the RDSR instruction isentered and remain low until the status data is read. Read-Status-Register is continuous with ongoing clock cyclesuntil it is terminated by a low to high transition of the CE#.See Figure 12 for the RDSR instruction sequence.
FIGURE 12: Read-Status-Register (RDSR) Sequence
CE#
SO
SI
SCK0 1 2 3 4 5 6 7
60
HIGH IMPEDANCE
MODE 0
MODE 3
1242 F10.0
MSB
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
1242 F11.0
MODE 3
SCK
SI
SO
CE#
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
05
MODE 0
HIGH IMPEDANCE
StatusRegister Out
MSB
MSB
14©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Write-Enable (WREN)
The Write-Enable (WREN) instruction sets the Write-Enable-Latch bit to 1 allowing Write operations to occur.The WREN instruction must be executed prior to any Write(Program/Erase) operation. CE# must be driven highbefore the WREN instruction is executed.
FIGURE 13: Write Enable (WREN) Sequence
Write-Disable (WRDI)
The Write-Disable (WRDI) instruction resets the Write-Enable-Latch bit and AAI bit to 0 disabling any new Writeoperations from occurring. CE# must be driven high beforethe WRDI instruction is executed.
FIGURE 14: Write Disable (WRDI) Sequence
Enable-Write-Status-Register (EWSR)
The Enable-Write-Status-Register (EWSR) instructionarms the Write-Status-Register (WRSR) instruction andopens the status register for alteration. The Enable-Write-Status-Register instruction does not have any effect andwill be wasted, if it is not followed immediately by the Write-Status-Register (WRSR) instruction. CE# must be drivenlow before the EWSR instruction is entered and must bedriven high before the EWSR instruction is executed.
CE#
SO
SI
SCK0 1 2 3 4 5 6 7
06
HIGH IMPEDANCE
MODE 0
MODE 3
1242 F12.0
MSB
CE#
SO
SI
SCK0 1 2 3 4 5 6 7
04
HIGH IMPEDANCE
MODE 0
MODE 3
1242 F13.0
MSB
15©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Write-Status-Register (WRSR)
The Write-Status-Register instruction works in conjunctionwith the Enable-Write-Status-Register (EWSR) instructionto write new values to the BP1, BP0, and BPL bits of thestatus register. The Write-Status-Register instruction mustbe executed immediately after the execution of the Enable-Write-Status-Register instruction (very next instruction buscycle). This two-step instruction sequence of the EWSRinstruction followed by the WRSR instruction works likeSDP (software data protection) command structure whichprevents any accidental alteration of the status register val-ues. The Write-Status-Register instruction will be ignoredwhen WP# is low and BPL bit is set to “1”. When the WP#is low, the BPL bit can only be set from “0” to “1” to lock-down the status register, but cannot be reset from “1” to “0”.
When WP# is high, the lock-down function of the BPL bit isdisabled and the BPL, BP0, and BP1 bits in the status reg-ister can all be changed. As long as BPL bit is set to 0 orWP# pin is driven high (VIH) prior to the low-to-high transi-tion of the CE# pin at the end of the WRSR instruction, theBP0, BP1, and BPL bit in the status register can all bealtered by the WRSR instruction. In this case, a singleWRSR instruction can set the BPL bit to “1” to lock downthe status register as well as altering the BP0 and BP1 bitat the same time. See Table 3 for a summary description ofWP# and BPL functions. CE# must be driven low beforethe command sequence of the WRSR instruction isentered and driven high before the WRSR instruction isexecuted. See Figure 15 for EWSR and WRSR instructionsequences.
FIGURE 15: Enable-Write-Status-Register (EWSR) and Write-Status-Register (WRSR) Sequence
1242 F14.0
MODE 3
HIGH IMPEDANCE
MODE 0
STATUSREGISTER IN
7 6 5 4 3 2 1 0
MSBMSBMSB
01
MODE 3
SCK
SI
SO
CE#
MODE 0
50
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
16©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
Read-ID
The Read-ID instruction identifies the devices asSST25LF020A and manufacturer as SST. The device infor-mation can be read from executing an 8-bit command, 90Hor ABH, followed by address bits [A23-A0]. Following theRead-ID instruction, the manufacturer’s ID is located in
address 00000H and the device ID is located in address00001H. Once the device is in Read-ID mode, the manu-facturer’s and device ID output data toggles betweenaddress 00000H and 00001H until terminated by a low tohigh transition on CE#.
FIGURE 16: Read-ID Sequence
1242 F15.0
CE#
SO
SI
SCK
00
0 1 2 3 4 5 6 7 8
00 ADD190 or AB
HIGH IMPEDANCE
15 16 23 24 31 32 39 40 47 48 55 56 63
BF Device ID BF Device ID
Note: The manufacturer's and device ID output stream is continuous until terminated by a low to high transition on CE#. 1. 00H will output the manfacturer's ID first and 01H will output device ID first before toggling between the two.
HIGHIMPEDANCE
MODE 3
MODE 0
MSB MSB
MSB
17©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
ELECTRICAL SPECIFICATIONS
Absolute Maximum Stress Ratings (Applied conditions greater than those listed under “Absolute Maximum StressRatings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device atthese conditions or conditions greater than those defined in the operational sections of this data sheet is not implied. Expo-sure to absolute maximum stress rating conditions may affect device reliability.)
Temperature Under Bias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55°C to +125°CStorage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65°C to +150°CD. C. Voltage on Any Pin to Ground Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to VDD+0.5VTransient Voltage (<20 ns) on Any Pin to Ground Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -2.0V to VDD+2.0VPackage Power Dissipation Capability (Ta = 25°C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0WSurface Mount Solder Reflow Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C for 10 secondsOutput Short Circuit Current1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 mA
1. Output shorted for no more than one second. No more than one output shorted at a time.
Operating Range:
Range Ambient Temp VDD
Commercial 0°C to +70°C 3.0-3.6V
Industrial -40°C to +85°C 3.0-3.6V
Extended -20°C to +85°C 3.0-3.6V
AC Conditions of Test
Input Rise/Fall Time . . . . . . . . . . . . . . . 5 ns
Output Load . . . . . . . . . . . . . . . . . . . . . CL = 30 pF
See Figures 21 and 22
TABLE 7: DC Operating Characteristics VDD = 3.0-3.6V
Symbol Parameter
Limits
Test ConditionsMin Max Units
IDDR Read Current 10 mA CE#=0.1 VDD/0.9 VDD@20 MHz, SO=open
IDDW Program and Erase Current 30 mA CE#=VDD
ISB Standby Current 15 µA CE#=VDD, VIN=VDD or VSS
ILI Input Leakage Current 1 µA VIN=GND to VDD, VDD=VDD Max
ILO Output Leakage Current 1 µA VOUT=GND to VDD, VDD=VDD Max
VIL Input Low Voltage 0.8 V VDD=VDD Min
VIH Input High Voltage 0.7 VDD V VDD=VDD Max
VOL Output Low Voltage 0.2 V IOL=100 µA, VDD=VDD Min
VOH Output High Voltage VDD-0.2 V IOH=-100 µA, VDD=VDD MinT7.0 1242
TABLE 8: Recommended System Power-up Timings
Symbol Parameter Minimum Units
TPU-READ1
1. This parameter is measured only for initial qualification and after a design or process change that could affect this parameter.
VDD Min to Read Operation 10 µs
TPU-WRITE1 VDD Min to Write Operation 10 µs
T8.0 1242
TABLE 9: Capacitance (Ta = 25°C, f=1 Mhz, other pins open)
Parameter Description Test Condition Maximum
COUT1
1. This parameter is measured only for initial qualification and after a design or process change that could affect this parameter.
Output Pin Capacitance VOUT = 0V 12 pF
CIN1 Input Capacitance VIN = 0V 6 pF
T9.0 1242
18©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
TABLE 10: Reliability Characteristics
Symbol Parameter Minimum Specification Units Test Method
NEND1 Endurance 10,000 Cycles JEDEC Standard A117
TDR1 Data Retention 100 Years JEDEC Standard A103
ILTH1 Latch Up 100 + IDD mA JEDEC Standard 78
T10.0 12421. This parameter is measured only for initial qualification and after a design or process change that could affect this parameter.
TABLE 11: AC Operating Characteristics VDD = 3.0-3.6V
Limits
20 MHz 33 MHz
Symbol Parameter Min Max Min Max Units
FCLK Serial Clock Frequency 20 33 MHz
TSCKH Serial Clock High Time 20 13 ns
TSCKL Serial Clock Low Time 20 13 ns
TCES1
1. Relative to SCK.
CE# Active Setup Time 20 12 ns
TCEH1 CE# Active Hold Time 20 12 ns
TCHS1 CE# Not Active Setup Time 10 10 ns
TCHH1 CE# Not Active Hold Time 10 10 ns
TCPH CE# High Time 100 100 ns
TCHZ CE# High to High-Z Output 20 14 ns
TCLZ SCK Low to Low-Z Output 0 0 ns
TDS Data In Setup Time 5 3 ns
TDH Data In Hold Time 5 3 ns
THLS HOLD# Low Setup Time 10 10 ns
THHS HOLD# High Setup Time 10 10 ns
THLH HOLD# Low Hold Time 15 10 ns
THHH HOLD# High Hold Time 10 10 ns
THZ HOLD# Low to High-Z Output 20 14 ns
TLZ HOLD# High to Low-Z Output 20 14 ns
TOH Output Hold from SCK Change 0 0 ns
TV Output Valid from SCK 20 12 ns
TSE Sector-Erase 25 25 ms
TBE Block-Erase 25 25 ms
TSCE Chip-Erase 100 100 ms
TBP Byte-Program 20 20 µsT11.0 1242
19©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
FIGURE 17: Serial Input Timing Diagram
FIGURE 18: Serial Output Timing Diagram
HIGH-Z HIGH-Z
CE#
SO
SI
SCK
MSB LSB
TDS TDH
TCHH
TCES TCEH TCHS
TSCKR
TSCKF
TCPH
1242 F16.0
1242 F17.0
CE#
SI
SO
SCK
MSB
TCLZ
TV
TSCKH
TCHZTOH
TSCKL
LSB
20©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
FIGURE 19: Hold Timing Diagram
FIGURE 20: Power-up Timing Diagram
THZ TLZ
THHH THLS
THLH
THHS
1242 F18.0
HOLD#
CE#
SCK
SO
SI
Time
VDD Min
VDD Max
VDD
Device fully accessibleTPU-READ
TPU-WRITE
Chip selection is not allowed.All commands are rejected by the device.
1242 F19.0
21©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
FIGURE 21: AC Input/Output Reference Waveforms
FIGURE 22: A Test Load Example
1242 F20.0
REFERENCE POINTS OUTPUTINPUT?
VHT
VLT
VHT
VLT
VIHT
VILT
AC test inputs are driven at VIHT (0.9VDD) for a logic “1” and VILT (0.1VDD) for a logic “0”. Measurement reference pointsfor inputs and outputs are VHT (0.7VDD) and VLT (0.3VDD). Input rise and fall times (10% ↔ 90%) are <5 ns.
Note: VHT - VHIGH TestVLT - VLOW TestVIHT - VINPUT HIGH TestVILT - VINPUT LOW Test
1242 F21.0
TO TESTER
TO DUT
CL
22©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
PRODUCT ORDERING INFORMATION
Valid combinations for SST25LF020A
SST25LF020A-33-4C-SAE SST25LF020A-33-4C-QAE
SST25LF020A-33-4I-SAE SST25LF020A-33-4I-QAE
SST25LF020A-33-4E-SAE SST25LF020A-33-4E-QAE
Note: Valid combinations are those products in mass production or will be in mass production. Consult your SST sales representative to confirm availability of valid combinations and to determine availability of new combinations.
SST 25 LF 020 A - 33 - 4I - SA EXX XX XXXX X - XXX - XX - XXX X
Environmental AttributeE1 = non-Pb
Package ModifierA = 8 leads or contacts
Package TypeS = SOIC 150 mil body widthQ = WSON
Operation TemperatureC = Commercial = 0°C to +70°CI = Industrial = -40°C to +85°CE = Extended = -20°C to +85°C
Minimum Endurance4 = 10,000 cycles
Operating Frequency33 = 33 MHz
Device Density020 = 2 Mbit
VoltageL = 3.0-3.6V
Product Series25 = Serial Peripheral Interface flash memory
1. Environmental suffix “E” denotes non-Pb solder. SST non-Pb solder devices are “RoHS Compliant”.
23©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
PACKAGING DIAGRAMS
FIGURE 23: 8-lead Small Outline Integrated Circuit (SOIC) 150 mil body width (4.9mm x 6mm)SST Package Code: SA
08-soic-5x6-SA-8Note: 1. Complies with JEDEC publication 95 MS-012 AA dimensions, although some dimensions may be more stringent. 2. All linear dimensions are in millimeters (max/min). 3. Coplanarity: 0.1 mm 4. Maximum allowable mold flash is 0.15 mm at the package ends and 0.25 mm between leads.
TOP VIEW SIDE VIEW
END VIEW
5.04.8
6.205.80
4.003.80
Pin #1Identifier
0.510.33
1.27 BSC
0.250.10
1.751.35
7°4 places
0.250.19
1.270.40
45° 7°4 places
0°
8°
1mm
24©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10
Data Sheet
2 Mbit SPI Serial FlashSST25LF020A
FIGURE 24: 8-contact Very-very-thin Small Outline No-lead (WSON)SST Package Code: QA
Note: 1. All linear dimensions are in millimeters (max/min). 2. Untoleranced dimensions (shown with box surround) are nominal target dimensions. 3. The external paddle is electrically connected to the die back-side and possibly to certain VSS leads. This paddle can be soldered to the PC board; it is suggested to connect this paddle to the VSS of the unit. Connection of this paddle to any other voltage potential can result in shorts and/or electrical malfunction of the device.
8-wson-5x6-QA-9.0
4.0
1.27 BSC
Pin #1
0.480.35
0.076
3.4
5.00 ± 0.10
6.00 ± 0.100.05 Max
0.700.50
0.800.70
0.800.70
Pin #1Corner
TOP VIEW BOTTOM VIEW
CROSS SECTION
SIDE VIEW
1mm
0.2
Silicon Storage Technology, Inc. • 1171 Sonora Court • Sunnyvale, CA 94086 • Telephone 408-735-9110 • Fax 408-735-9036www.SuperFlash.com or www.sst.com
TABLE 12: Revision History
Number Description Date
00 • Initial release of S71242 Aug 2003
01 • Added new 8-SOIC (S2A) package and associated MPNs Oct 2003
02 • 2004 Data Book• Updated the Package Outline for S2A
Dec 2003
03 • Document status changed from “Advance Information” to “Preliminary Specifications”• Added Commercial and Extended temperatures and associated MPNs
Jun 2004
04 • Revised Absolute Max. Stress Ratings for Surface Mount Solder Reflow Temp.• Migrated document from Preliminary Specifications to Data Sheet
Nov 2005
05 • Updated QA package drawing to version 9.• Removed leaded part numbers.• Added footnote to Product Ordering Information section.
Jan 2006
06 • End of life all valid combinations of SST25LF040A. See S71242(01) Mar 2009
07 • Removed 4Mbit information inadvertently missed in last EOL revision Jan 2010
25©2010 Silicon Storage Technology, Inc. S71242-07-000 01/10